DIY top end job - am I crazy? Or is this possible?
I sailed my old but new to me boat home this weekend, a Cape Dory 28, and it seems as though the engine top end is going to need some serious work.
On this trip, we overheated three times, and killed the engine within 30 seconds once, and more like 10 seconds the other two times. Repairs were performed twice – impeller replacement the first time and a hose from the water-cooled exhaust the second. On the third overheat, we just let the engine cool for an hour, and felt this was caused by having sails up for 15 minutes with the engine idling in neutral, and the boat going on her ear. Our thinking was that air had got taken into the cooling system while heeling, and this had caused the problem. Of course, this thinking may be entirely flawed.
Then, after motoring happily and a nice cool engine temperature for an hour or so, the engine started making a vastly different sound – I suppose one could describe it as a rattle from the valve area. The engine was killed within seconds, allowed to cool for an hour, then restarted. It immediately made a much louder version of the first sound. The engine was killed instantly, hasn't been restarted since.
This is a Volvo Penta MD2B, by the way, which was sounding absolutely fabulous until the rattling started.
We didn’t try the engine again, and sailed 120 miles down the Hudson and into our slip in Brooklyn. This was interesting, to say the least! Perhaps I’ll write a diary of my trip, but right now, I want an engine so I can go sailing.
My semi-knowledgeable companions on board thought I was going to need a top-end job.
Today, two days after we got back to Brooklyn, we looked under the valve cover and there seemed to be some oil, but not a lot. I take this to be because the engine hadn’t been run in 3 days and most of the oil had run off by now. The engine oil in the sump is full and clean.
Of course, here in the northeast, we’re getting started for the season, and all reputable diesel mechanics are way too busy to talk to the likes of me. So my question is, how smart or foolish is it for me to attempt this job myself. Obviously, there’s some machining to be done, and new parts to buy, and I expect to take the head to a good shop (perhaps an auto one?) for some of the work. But I am considering doing most of this myself, with the assistance of semi-knowledgeable friends.
My own mechanical skills are limited, but not without capability. I have worked on a lot of motorcycles, for example. But never a diesel marine engine. One friend who wants to work on this with me is considerably more knowledgeable, but this would be a first for him, too.
Am I crazy to try? What good resources are there out there that could help me through this? I’m not even sure how to tell if my valves need work, or if the problem is something else. But the nasty noises did indeed seem to be coming from that part of the engine.
(Of course, if anyone reading this in the NYC area wants a gig, they are welcome to apply!)